Implementation of EPA's 1997 Ozone and Particulate Matter Air Quality Standards
EPA Revokes 1-Hour Ground-Level Ozone (Smog) Standard for Many Counties
Note: EPA no longer updates this information, but it may be useful as a reference or resource.Note: EPA no longer updates this information, but it may be useful as a reference or resource.
December 29, 1997
STANDARD FOR MANY COUNTIES
Direct Final Rule: Federal Register Notice
Proposed Rule: Federal Register Notice
Today's Action...
This week, the Environmental Protection Agency (EPA) is releasing the list of counties for which the Agency has revoked the 1-hour national ambient air quality standard for ground-level ozone (smog). The 1-hour standard is being revoked for counties that have not measured a violation of the 1-hour ozone standard over the most recently available three year period of time (generally using air quality data from 1994-1996).
The list includes counties that were formerly in "nonattainment"status, counties that have monitored clean air for many years, and counties that for one reason or another do not normally monitor for ozone (e.g. because they are unlikely to have an ozone problem).
Although the 1-hour standard no longer applies in these counties, the new, more protective 8-hour standard does apply. In the year 2000 EPA will formally determine which areas of the country do not meet its new 8-hour ozone standard and "designate" them as "nonattainment." In the interim, all areas of the country must continue to implement the programs that led to their attaining the 1-hour standard.
Reaching attainment with the 1-hour standard, as reflected in today's notice, is an important step towards either:
Reaching attainment with the new 8-hour standard: areas that are included on this list today (and those that subsequently meet the 1-hour standard before the year 2000) and likewise meet the 8-hour standard in the year 2000 will be considered "attainment" areas for ground-level ozone.
or
Being classified as a new "transitional" area: areas that are included on this list today (but that do not meet the 8-hour standard when EPA designates areas for that standard in the year 2000), may be eligible for a special "transitional" classification, provided they meet other criteria.
Background
On July 17, 1997, following a lengthy scientific review process, the EPA revised the national ambient air quality standard for ground-level ozone. Specifically, the EPA is phasing out and replacing the previous 1-hour standard with a new 8-hour standard that is more protective of public health.
In the year 2000, EPA will designate areas which do not meet the 8-hour standard based on the most recently available 3 years of ozone data available at that time (e.g., 1997-1999).
When EPA issued the revised standards in July 1997, President Clinton issued a memorandum which outlined a common-sense implementation strategy for both the 8-hour and 1-hour ozone standard. One of the first steps for areas to take toward eventually meeting the new 8-hour ozone standard is to meet the 1-hour standard. As called for in that memorandum, EPA is publishing the list of counties for which the 1-hour standard is no longer applicable. In making these determinations, EPA used the most recent 3 years worth of ozone data (1994-1996).
In early 1998, EPA will have additional quality-assured data for 1997. At that time, the Agency intends to take action to revoke the 1-hour standard in additional areas that do not violate the 1-hour standard based on the new data (1995-1997). Furthermore, EPA intends to publish, on an annual basis, similar actions identifying areas where the 1-hour standard is no longer applicable.
Of the counties for which the 1-hour standard is being revoked today, 437 have monitors that measure attainment with the 1-hour standard; and 2465 do not have monitored data (e.g. the area has no monitors because it is unlikely to have an ozone problem). Of this total number, 207 counties were formerly designated as nonattainment. [Note: many of these 207 counties had monitors that violated the standard in the past, others were counties that had no monitors, but were part of a larger metropolitan statistical area with monitors in other counties that violated the 1-hour standard.]
For Further Information
General questions concerning the notice should be referred to Annie Nikbakht (policy issues) at 919 541-5246 or Barry Gilbert (air quality data issues) at 919 541-5238.
More detailed information including county lists, maps, Federal Register Notices, Technical Support Document, and air quality data are available at EPA's Green Book web site.